1. A microphone, an operational amplifier to amplify the sound, something to make the sound into a pulse - Personally I would use a microprocessor and feed the sound into the analogue input and detect level or use the counter function to detect a given frequency.
2. Depends on the type of sound you want - The microprocessor will make simple sounds or trigger an MP3 player for more complex sounds.
This isn't going to be a beginners project I suggest you start by reading through
Discussions
1. Something to detect the beep
2. Something to play the sound
1. A microphone, an operational amplifier to amplify the sound, something to make the sound into a pulse - Personally I would use a microprocessor and feed the sound into the analogue input and detect level or use the counter function to detect a given frequency.
2. Depends on the type of sound you want - The microprocessor will make simple sounds or trigger an MP3 player for more complex sounds.
This isn't going to be a beginners project I suggest you start by reading through
http://www.picaxe.com/Getting-Started/PICAXE-Manuals/
...or the old 567 tone decoder....